User manual

Adit 3200 - Release 1.6 Glossary-11
Glossary
PPP
PPP Point-to-Point Protocol. is used for establishing a point-to-point link that provides a single,
preestablished WAN communications path from the customer premises, through a carrier
network (the telephone company), to a remote network
PPPoT1 Point-to-Point over T1.
PRACK Provisionable acknowledgement.
Primary Rate Interface
(PRI)
The ISDN equivalent of a T1. The Primary Rate Interface (delivered to the customer’s
premise) provides 23B+D (N.America) or 30B+D (Europe) running at 1.544 Mb/sec and
2.048 Mb/sec, respectively.
protocol Procedure or set of rules.
PVC Permanent Virtual Circuit. A PVC is a permanent channel connection between two ATM
devices. PVC’s allow network transmissions to be started without having to first establish
a connection with the end point ATM device. When a PVC is constructed, the end points
of the connection will agree upon a path in which data will travel, and therefore agree upon
the route that data will travel to reach its destination.
Quality of Service (QoS) The measure of the telephone service quality provided to a subscriber.
RADIUS Remote Authentication Dial-In Service. RADIUS is a client/server-based authentication
software system. The software supports remote access applications, allowing an
organization to maintain user profiles in a centralized database residing on an
authentication server which can be shared by multiple remote access servers.
robbed bit A type of analog signaling that will occasionally steal information bits used for circuit
signaling coding.
router A computer or internet working device that directs traffic and moves packets between
networks. A hardware architecture used in LANs, MANs, WANs, the Internet and
Intranets. A device that connects any number of LANs. Routers use headers and a
forwarding table to determine where packets go, and they use ICMP to communicate with
each other and configure the best route between any two hosts.
Router Information
Protocol (RIP)
RIP is based on distance vector algorithms that measure the shortest path between two
points on a network, based on the addresses of the originating and destination devices. The
shortest path is determined by the number of hops between those points. Each router
maintains a routing table, or routing database, of known addresses and routes; each router
periodically broadcasts the contents of its table to neighboring routers in order that the
entire network can maintain a synchronized database.
Router Information
Protocol Version 1
(RIPv1)
Original version of RIP. This is a classful routing protocol, it does not have the ability to
transmit the subnet mask within its updates. RIP v1 imposes the subnet mask on the
inbound interface and this is normally defined by the engineer. Learned routes are entered
into the routing table with their natural mask. As a result there can be a great waste of
internet host addresses.
Router Information
Protocol Version 2
(RIPv2)
Second version of RIP, additional to Version 1, enables the use of a simple authentication
mechanism to secure table updates. More importantly, RIP 2 supports subnet masks, a
critical feature that is not available in RIP (v1).